Electron-discharge devices



Sept. 3, 1957 w. c. BROWN ELECTRON-DISCHARGE DEVICES Original Filed July 17, 1946 2 Sheets-Sheet 1 Y N n Em yf w M 00m o c 0 3 3 W f//f H 3/ U M BY a fr C/ w T/ Q,, w PU mi, \I.`,.,|wi.`.,,.\ III [I 1 6 W -2 -M m... mwwflh 1 1 JM fp lrlwdlr il. E 1.5 .1 U I 7 s; HIM Il# bwhlv/w ,M lr|lidiiflnv 7 2 4\ Q 2 WATER Sept- 3 1957 w. c. BROWN 2,805,361

@mamon-DISCHARGE DEVICES originan Filed July 17. 194s 2 sheets-sheet 2 /NvsNroR W11. IAM C. Bmw/v 2,805,361 Patented Sept. 3, 1957 ELECTRON-DISCHARGE DEVICES William C. Brown, Lincoln, Mass., assigner to Raytheon Manufacturing Company, Newton, Mass., a corporation of Delaware Original application July 17, 1946, Serial No. 684,110, now Patent No. 2,615,143, dated October 21, 1952. Divided and this application March 5, 1952, Serial No. 274,949

4 Claims. (Cl. S15-39.51)

This is a division of my copending application, Serial No. 684,110, filed July 17, 1946, now Patent No. 2,615,- 143, dated October 21, 1952.

This invention relates to electron-discharge devices, and, more particularly, to electron-discharge devices of the type known as multiple-anode magnetrons.

Such devices generally have frequency-controlling circuits incorporated directly therein, for which reason their dimensions become prohibitively large when used, for example, in the middle region of the very-high frequency band of the electromagnetic spectrum, such as from 100 to 200 megacycles. This is especially so where such devices are intended for generating power of appreciable magnitude.

lt is, therefore, the main object of the present invention to provide an electron-discharge device of the general character indicated, for use at the frequencies to which reference has been made, without requiring components of impractical proportions.

lt is a further object of the present invention so to construct an electron-discharge device of the above-mentioned type as to enable the same to handle appreciable power without overheating, yet requiring no elaborate auxiliary means for maintaining the same at a reasonable temperature.

These, and other objects of the present invention, which will become more apparent as the detailed description thereof progresses, are attained, briey, in the following manner.

The electron-discharge device of the present invention contemplates the provision of an envelope, preferably, of cylindrical form, and made, preferably, of magnetic material, such as steel. Axially disposed within said envelope, and supported, for example, from one of the end walls thereof, is a cathode, and extending interiorly from one or both of the end walls of said envelope, longitudinally of said envelope and coaxially about said cathode, is a plurality of anode members. Preferably, each of said anode members includes a fluid-receiving element for cooling the same, said element communicating with the exterior of the envelope in order to receive the cooling fluid from a iiuid supply channel common to the uid intakes of all the fluid-receiving elements, and to exhaust the iluid. Such an arrangement for supplying iluid to the Huid-receiving elements will be referred to herein by expressing the fluid-receiving elements as being hydraulically in parallel. Each of said members further includes an electron-receiving element which is carried by said fluidreceiving element in spaced relationship to the cathode of the device. Said anode members are of such physical length and are so spaced from each other that each pair of adjacent members, together with the supporting portions of the wall of the envelope lying therebetween, constitutes a transmission line whose electrical length is such that it is resonant at the frequency desired of the output of the device.

As will later be described in greater detail, the present invention may take more than one form. In one of these forms, the anode members are supported from opposite end walls of the envelope and are of an electrical length substantially equal to the length of a half-wave at the resonant frequency of the device. In this case, the electron-receiving elements are carried by the huid-receiving elements midway along the length of the latter, so that each pair of adjacent anode members, together with the envelope wall portions therebetween, defines a pair of parallel-connected, shorted quarter-wave transmission Iines adapted to resonate at the output frequency of the device.

In another form of the present invention, the anode members are supported only from one of the end walls of the envelope, the duid-receiving element of each anode member being closed at its inner end, and open at its outer end to communicate with the exterior of the envelope. The electron-receiving elements are carried by the Huid-receiving elements adjacent their inner closed ends, and, in this case, the electrical length of each tiuid-receiving element is substantially equal to the length of a quarter-wave at the resonant frequency of the device, whereby each pair of adjacent anode members, together with that portion of the supporting wall of the envelope lying therebetween, constitutes a shorted, quarter-wave transmission line.

Each of the embodiments above referred to is completed by a pair of opposed magnetic pole pieces supported by the opposite end walls of the envelope, said pole pieces being adapted to establish a magnetic field transversely of the electron path between the cathode and anode members of the device, the envelope, in one of said embodiments of the device, constituting a return path for the magnetic ilux.

In the accompanying specification there shall be described, and in the annexed drawings shown, two illustrative embodiments of the electron-discharge devices of the present invention. Itis, however, to be clearly understood that the present invention is not to be limited to the details herein shown and described for purposes of illustration only, inasmuch as changes therein may be made without the exercise of invention, and within the true spirit and scope of the claims hereto appended.

ln said drawings:

Fig. 1 is a longitudinal sectional view taken substantially through the center of the first of the embodiments of the electron-discharge devices of the present invention above brieily described; and

Fig. 2 is a similar view of the second of the embodiments of the present invention above brieily described.

Referring now more in detail to the embodiment of the present invention shown in Fig. 1 of the drawings, the numeral 10 designates a hollow tubular, for example, cylindrical body closed at its ends by end plates 11 and 12, said body and end plates constituting a hermetically sealed envelope made, preferably, of magnetic material, such as steel.

Centrally disposed within said envelope is a cathode sleeve 13 made, preferably, of nickel, said sleeve being provided, adjacent its inner end, with spaced shields 14 intermediate which said sleeve is provided with an electron-emissive coating 15, for example, of the alkalineearth metal oxide type. The sleeve 13 may be supported from one of the end plates 11 or 12, here shown as the end plate 12, by securing the same to a bushing 16 to which is ail'ixed an insulator 17, the opposite end of which is atiixed to a ring 18 carried by the end plate 12. The bushing 16 and the ring 18 are made, preferably, of the material known as Kovar, and the insulator 17 may be made of glass. Thus, the cathode structure is electrically isolated from the envelope structure.

A cathode heater 19 is mounted within the sleeve 13 as by having one end 20 thereof electrically connected to the upper shield 14 and the other, lead-in end 21, thereof passing downwardly through said sleeve and being supported therein by glass beads 22 and 23. Current may be supplied to the heater 19 by connecting one end of a voltage source to the sleeve 13, the other end of said voltage source being connected to the lead-in end 21 of said heater.

Supported from the end plates 11 and 12, and extending longitudinally of the cylindrical body 10, is a plurality of anode members 24, said anode members being uniformly spaced from each other and concentrically disposed about the cathode sleeve 13. Each of said anode members includes a tubular, duid-receiving element 25 made, preferably, of copper, and being of a length corresponding to that of a half-wave at the frequency desired of the output of the device. Carried by each of said fluid-receiving elements, at a point midway along the length thereoi, so as to face the coated portion of the cathode sieeve i3, is an electron-receiving block 26 made, preferably. of copper. The arrangement is such that the upper and lower halves of each pair of adjacent anode members. together with those portions of the end plates 1l and 12 lying. respectively, therebetween, constitute parallel-connected. shorted quarter-wave transmission lines which are resonant to the output frequency of the device.

in order to dissipate the heat developed in the anode members 24, the tubular elements 25 thereof communicate at their ends with toroidal headers 27 and 28, the former receiving a cooling fluid, such as water, from an inlet pipe 29, and the latter expelling said duid, after the same has passed through the elements 25, by way of an outlet pipe 30.

ln order to establish a magnetic eld in a direction perpendicular to the electron path between the cathode 13 and the anode members 24, with which devices of the magnetron type are usually provided, the end plates 11 and 12 carry inwardly extending tubular magnets 31 and 32 of opposite polarity, said end plates and the cylindricul body llt therebetween providing the return path for thc ilux of .said magnets.

The device is completed by a conductor 33 electrically connected to any one of the anode members 24, said conductor passing through a pipe 34 threadedly engaged in the cylindrical body l0. The conductor 33 and the pipe 34 constitute. respectively, the inner and outer conductors oi a coaxial transmission line by means of which the oscillations generated within the device may be conveyed to any utilization circuit.

Reference is now had to the embodiment of the present invention shown in Fig. 2 of the drawings. As there shown. the device comprises an envelope consisting of a cylindrical body 35 closed at one end by an end plate 36 and carrying near its other end a plate 37, in this case, made, however. of copper.

Axially disposed in said cylindrical body 35, and supported irc-m the plate 36, is a cathode sleeve 38 made, preferably, of nickel, said sleeve being provided, at its inner end. with a pair of spaced shields 39 between which said sleeve is coated, its at 46, with an electron-emissive material. for example, the oxide of an alkaline-earth metal. The sleeve 35 is fixed in a bushing 41 sealed to the lower end ol an insulator 42, the upper end of said insulator being sealed to a ring 43 carried by a anged. tubular pole piece @E4 which extends into the envelope through a central opening in the end plate 36 thereof. The bushing 4i and thc ring 43 may be made of the matcrial known as Kovar, and the insulator 42 may be made of glass.

The cathode slccvc 38 is provided with a heater 44', one end 45 of which is electrically connected to the upper shield 39, and the other, lead-in end 46, of which passes downwardly through said sleeve 38, being spaced therefrom by a glass bead 47. Thus, current may be supplied to the heater 44 by connecting the sleeve 38 to one terminal of a voltage source, and connecting the lead-in end 46 to the other terminal of said voltage source.

Extending downwardly from the plate 37, uniformly spaced from each other and concentrically disposed about the cathode sleeve 38, is a plurality of anode members 48 made, preferably, of copper, each comprising a tubular, Huid-receiving element 49, open at its upper end and closed at its lower end, each such huid-receiving element carrying, adjacent its lower end, an electron-receiving block 50. Each anode member 43 is of such physical length that each pair of adjacent members, together with that portion of the plate 37 lying therebetween, consti` tutes a shorted, quarter-wave transmission line at the frequency desired of the output of the device.

The plate 37, together with a ring 51, seated upon the cylindrical body 3S, and an end plate 52, provided with a magnet-receiving socket 53 extending into the envelope through a central opening formed in said plate 37, constitute a header divided into incoming and outgoing uidreceiving compartments by a bate 54. The bale 54 carries a plurality of pipes 55 which communicate with the upper or incoming fluid-receiving compartment of the header, and which extend downwardly into the uidreceiving elements 49 of the anode members 48, said pipes being open at their lower ends and terminating short of the closed ends of said fluid-receiving elements 49. A cooling duid, such as water, enters the header through an inlet pipe 56, passes to the elements 49 through the pipes 55, enters the lower or outgoing compartment of the header from thc upper open ends of said elements 49, and leaves the device through an outlet pipe 57.

The socket 53 is receptive ol a pole piece 58, said pole piece and the pole piece engaging plate 36 terminating a magnet 59, whereby a magnetic field is established in the space between the cathode sleeve 38 and the anode members 48, in a direction perpendicular to the electron path between said cathode and said anode members.

The device is completed by a conductor 60 electrically connected to the tubular element 49 lof any one of the anode members 48, said conductor passing out of the device through the cylindrical body 35 and constituting, together with a pipe 61, threadedly engaged in said cylindrical body, a coaxial transmission line for conveying the oscillations generated in said device to any utilization circuit.

This completes the description of the aforesaid illustrative embodiments of the present invention. It will be noted from all of the foregoing that, by reason of the disposition of the anode members within the envelope, the device is readily adapted for use at frequencies in the middle region of the very-high frequency band of the spectrum, and that the components making up the device are of practical proportions. It will further be noted that, by reason of the aforesaid arrangement of the anode members within the envelope, and the simple manner of cooling said anode members, the devices are capable of handling appreciable power without overheating.

These, and other objects and advantages of the present invention, will readily occur to those skilled in the art to which the same relates.

What is claimed is:

l. An electron-discharge device comprising a source of electrons, a signal wave transmission structure spaced from and adjacent to said source, said structure comprising a plurality of spaced conductors, a header forming a portion of a huid-circulating path and having an input channel for admitting a cooling fluid and an output channel through which the fluid is removed, each of said conductors comprising a. fluid-receiving element closed at one end and communicating only with said input channel at the other end, a fluid carrying member open at both ends and positioned within said duid-receiving element, said uid carrying member communicating at one end thereof with said output channel only, said elements and members being connected to said header hydraulically in parallel, and means for directing electrons from said source along paths adjacent said structure.

2. An electron-discharge device comprising: an envelope; a cathode supported within said envelope; and a plurality of anode members extending interiorly from one of the walls of said envelope; a header forming a portion of a uidcirculating path and partially bounded by said one wall, said header having an input channel for admitting a cooling fluid and an output channel through which the iluid is removed, each of said anode members including a Huid-receiving element closed at one end and open at the other end to communicate only with the exterior of said envelope, and an electron-receiving element carried adjacent the closed end of said Huid-receiving element in spaced relationship to said cathode; each pair of adjacent anode members, together with that portion of the wall of said envelope lying therebetween, constituting a shorted, quarter-wave transmission line adapted to resonate at the frequency of said device.

3. An electron-discharge device comprising: a cylindri cal envelope; a cathode supported within said envelope; and a plurality of anode members extending interiorly from one of the end walls of said envelope; said anode members being disposed longitudinally of said envelope, circumferentially about said cathode; a header forming a portion of a huid-circulating path and having an input channel for admitting a cooling uid and an output channel through which the fluid is removed, each of said anode members including a fluid-receiving element closed at one end and open at the other end to communicate only with said input channel at the other end, and an electron-receiving element carried adjacent the closed end of said fluid-receiving element in spaced relationship to said cathode, each pair of adjacent anode members, together with that portion of said end wall of said envelope lying therebetween, constituting a shorted, quarter-wave transmission line adapted to resonate at the frequency of the output of said device.

4. An electron-discharge device comprising: a cy1indrical envelope of magnetic material, a cathode supported within said envelope; a plurality of anode members extending interiorly from one of the end walls of said envelope; and a pair of pole pieces supported by said end walls and adapted to establish a magnetic field transversely of the electron path between said cathode and said anode members; said anode members being disposed longitudinally of said envelope, circumferentially about said cathode; each of said anode members including a fluid-receiving element closed at one end and open at the other end to communicate only with said input channel at the other end, an an electron-receiving element carried adjacent the closed end of said fluid-receiving element in spaced relationship to said cathode; a fluid carrying member open at both ends and positioned within said fluid-receiving element, each pair of adjacent anode members, together with that portion of said first-named end wall of said envelope lying therebetween, constituting a shorted, quarter-wave transmission line adapted to resonate at the frequency of the output of said device.

References Cited in the le of this patent UNITED STATES PATENTS 1,361,099 Round Dec. 7, 1920 2,189,501 Helbig Feb. 6, 1940 2,201,216 Baier et al. May 21, 1940 2,409,694 Laidig Oct. 22, 1946 2,428,193 Blewett Sept. 30, 1947 2,460,119 Blewett et al. Ian. 25, 1949 2,480,999 Brown et al. Sept. 6, 1949 2,496,887 Nelson Feb. 7, 1950 2,502,405 Brown Mar. 28, 1950 2,546,773 Nelson Mar. 27, 1951 

